Combination sound converters and spark arrestors



Oct. 25., 1955 c. N. HOPKINS COMBINATION SOUND CONVERTERS AND SPARK ARRESTORS Filed Feb. 14, 1952 INVENTOR. CLARENCE N. HOPKINS ATTORNEY United States Patent COMBINATIQN SOUND CNVERTERS ANB SPARK ARRESTORS Clarence N. Hopkins, Portland, Greg. Application February 14, 1952, Serial No. 271,5?6 4 Claims. (Cl. 181-43) This invention relates to a combination sound converter and spark arrestor, and is particularly adapted to be installed on exhaust pipes on trucks, tractors, marine engines and the like.

The primary object of the invention is to convert the high pitch or cracking exhaust sounds into a more pleasing sound to the ear.

A series of sound converting chambers are arranged adjacent one another within the converter to receive the exhaust sounds of high and low pitches, blending them together, thereby giving oil' a steady even exhaust sound, eliminating the harsh cracking exhaust sounds now present in exhaust pipes of trucks, tractors, marine engines and the like.

A still further object of this invention is to convert undesirable exhaust noises into softer and unobjectionable tones, offering a minimum resistance to the iiow of the exhaust gases.

Sound converting chambers are located around the flow of gases passing through the converter for receiving the sounds, but not obstructing the flow of exhaust gases.

Another object of my invention is to arrest or eliminate sparks from the exhaust gases on motor vehicles, eliminating re hazards created by said motor vehicles.

These and other incidental objects will be apparent in the drawings, specification and claims.

Referring to the drawings:

Figure l is a side view of my new and improved combination sound converter and spark arrestor.

Figure 2 is a side sectional View, taken on line 2-2 of Figure l.

Figure 3 is a plan sectional view, taken on line 3 3 of Figure l.

Figure 4 is a perspective view of the converter, partially broken away for illustrating the sound converting chambers.

Figure 5 shows another preferred method of injecting water into the exhaust stream before entering the converter.

Referring more specifically to the drawings:

My new and improved sound converter consists of a drum 1, having ends 2 and 3 forming part thereof. These ends have collars 4 adapted to be connected to the exhaust pipe line by any suitable means, the pipe line being indicated in broken lines in Figure l.

Sound converting chambers 5 in the shape of doughnuts are stacked one upon the other within the cylinder l, as best illustrated in Figures 2, 3 and 4. These chambers are slit around their' inner diameters as indicated at 6, Figure 2.

Exhaust gases enter through the collar 4 of the end 3 in the direction of the arrows, Figure 2, passing through the converter and out the end 2 by way of the collar 4, thence out through the exhaust pipe. The slits 6 located on the inner diameters of the chambers 5 are narrower where the gases enter the converter, increasing in width towards the discharge end of the converter.

Through experimental work in the construction of the converter, I have found that this has something to do with the conversion of the exhaust sounds. As the gases pass through the center of the converter chambers, indicated by numeral 5A, referring to Figure 3, it is assumed that that the sound from the exhaust gases will pass through the slots 6 into the converters due to the fact that sounds expand radially from the stream of exhaust gases while passing through the converter. It is believed that the narrow slits receive the high pitch sound, while the wider slits receive the lower pitch sound, dissipating and mixing them together in an even exhaust tone when the exhaust leaves the converter.

Some of the heat from the gases entering the chambers 5 escapes through the openings 7 into the drum 1, from where the heat is radiated into the atmosphere. This helps to convert the harsh exhaust sounds entering into the chambers 5 to the desired tone.

By building my converter as illustrated in the drawings, excellent results are obtained. The above description of what happens is more or less assumed. These converters are being used today extensively with excellent results.

I do not claim to reduce the overall exhaust noise to any great degree, but I do claim that a more pleasing mellowed exhaust tone is produced, one that is not objectionable to the law enforcement officers throughout the country.

I have included a sparlf` arresting feature in combination with my sound converter. l have found that by admitting water into the sound converting chambers as indicated particularly in Figure 2, the exhaust gases convert this water into a tine fog on the way through the converter, arresting or damping any sparks passing through the converter.

This water l' is introduced into the chambers 5 from a manifold 8. Pipes 9, 10, il, .l2 and 13 lead from the manifold 8 into the chambers 5 at any suitable point, as for instance at 14. The upper ends 15 of the pipes ter* minate above the bottom i6 of the manifold 8, the object of which is to insure a uniform distribution of the water 17 within the manifold to the chambers.

Water is supplied into the manifold 8 by way of the pipe 1S which is connected to the manifold at 19 and leads from a water supply. The amount of flow of water being controlled by the valve Ztl. Water may be supplied by gravity or by a positive pumping means.

Figure 5 illustrates a pipe 2l, supplying water through a control valve 22 to a nozzle 23 within the exhaust pipe. By injecting the water into the exhaust stream ahead of the converter the said water is broken up into a fog by the converter.

in the operation of the spark arresting feature, the exhaust gases enter the slots 6 of the chambers 5, picking up the water within the chambers, converting the same into a ne fog which enters the exhaust stream, passing out of the converter with the exhaust gases, completely arresting or damping any sparks that may be flowing through the exhaust pipe.

What i claim is:

l. A sound converter comprisins7 a cylindrical casing having axially disposed inlet and outlet openings in the opposite end walls thereof, and a plurality of doughnutshaped expansion chamber forming shells successively nested in said casing between the end walls thereof, said shells having outer peripheries contacting the cylindrictl wall of said casing and inner peripheries of a diameter substantially equal to the diameters of said inlet and outlet openings and forming a continuous passage of substantially uniform diameter through said casing, the inner peripheries of said shells each having a continuous slot therearound and placing the expansion chambers within said shells in direct communication with said passage,

said shells each having openings in the outer peripheral portions thereof to pass heat to the casing walls, said openings being increasingly larger in successive shells from the inlet to the outlet ends.

2, A sound converter as dened in claim l wherein said shells are of uniform size and said slots are of successively increasing width in successive shells from the inlet to the outlet ends.

3. A sound converter comprising a cylindrical casing having axially disposed inlet and outlet openings in the opposite end walls thereof, a plurality of doughnutshaped expansion chamber forming shells successively nested in said casing between the end walls thereof, said shells having outer peripheries contacting the cylindrical wall of said casing and inner peripheries of a diameter substantially equal to the diameters of said inlet and outlet openings and forming a continuous passage of substantially uniform diameter through said casing, the inner peripheries of said shells each having a continuous slot therearound and placing the expansion chambers within said shells in direct communication with said passage,

said casing being adapted to be disposed on a vertical axis with said shells horizontal and the lower portions of said shells forming troughs, and liquid supply tubes extending through said casing to the trough portions of said shells, and means for supplying liquid to said tubes.

4. A sound converter as defined in claim 3 wherein said liquid supplying means comprises a liquid reservoir on the upper end portion of said casing.

References Cited in the le of this patent UNITED STATES PATENTS 951,770 Miller Mar. 8, 1910 1,109,547 Robinson Sept. 1, 1914 1,822,990 Gorsline Sept. l5, 1931 1,990,837 Morgenstern Feb. 12, 1935 2,013,956 Heath Sept.V 10, 1935 2,241,729 McCurdy May 13, 1941 2,286,683 McCurdy June 16, 1942 2,455,965 Wohlberg Dec. 14, 1948 

